1989 Fiscal Year Final Research Report Summary
Improved Plasma Confinement in ULQ Discharge
| Project/Area Number |
63420050
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
プラズマ理工学
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| Research Institution | Faculty of Engneering, University of Tokyo |
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Principal Investigator |
INOUE Nobuyuki University of Tokyo, Dept.Nucl.Engr., professor, 工学部, 教授 (60023719)
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| Co-Investigator(Kenkyū-buntansha) |
TOYAMA Hiroshi University of Tokyo, Dept.Phys., Assistant professor, 理学部, 助教授 (50023718)
MIYAMOTO Kenro University of Tokyo, Dept.Phys., professor, 理学部, 教授 (60023701)
MORIKAWA Junji University of Tokyo, Dept.Nucl.Engr., Tech.Staf., 工学部, 教務職員 (70192375)
NIHEI Hitoshi University of Tokyo, Dept.Nucl.Engr., Rec.Asoc., 工学部, 助手 (70010973)
YOSHIDA Zensho University of Tokyo, Dept.Nucl.Engr., Assistant professor, 工学部, 助教授 (80182765)
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| Project Period (FY) |
1988 – 1989
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| Keywords | ULQ / Plasma / Nuclear Fusion / Plasma Confinement / Resistance Anomaly |
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| Research Abstract |
The ULQ configuration is a high-current and low-magnetic-field plasma equilibrium, which is expected to confine a high-beta plasma. The stable ULQ discharge condition was originally found by on the REPUTE-1 device at the University of Tokyo. After that, the plasma confinement characteristics have been studied in many different experiments, and basic scalings of confinement have been developed. In the present study, a higher-toroidal-field ULQ has been studied on a new device REPUTE-1Q.The maximum toroidal field is 0.7T,the maximum plasma current is 130kA,the major and minor radii are, respecively, 0.55m and 0.15m. Stable ULQ discharges are obtained with externally applied vertical field. No conducting shell is found to be necessary to stabilize the discharge. The effective plasma resistivity is reduced down to 3 m, which is about one half of the minimum value obtained in REPUTE-1, and significant improvement of the confinement is confirmed. REPUTE-1Q,can also be operated in the very low q (VLQ) regime of tokamak. Setup conditions for stable VLQ discharges have been studied. In the Hugill diagram to classify toroidal discharges, the ULQ and VLQ plasmas in REPUTE-1Q are lying in a relatively lower density and lower q regime. The experimental data obtained provide general understandings of discharge plasmas.
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